What is a cycle time scatter plot?
The cycle time scatter plot is an adapted version of the well-known chart. It is revered in the Lean management world because it provides a very detailed picture of one of the key metrics in Lean – cycle time.
Cycle time is a representation of how long it takes to get things done for individual items on your Kanban boards. The goal of a cycle time scatter plot is to visualize the cycle time of your team’s assignments within a predefined time frame.
The structure of this chart is very similar to that of a typical scatter plot. The horizontal axis of the chart visualizes a selected time frame by dates. The vertical one represents the cycle time of the tasks that were completed during this period calculated in days.
Each dot that you see scattered across the chart is a marker representing a task within a card on your Kanban board. The positions of the dots are determined by the date of completion and how long it required for the Kanban card to reach the done column.
A leader practicing Lean management may use the cycle time scatter plot to:
- Visualize clearly the cycle times of multiple assignments of a kind
- Compare how much time different work types take by coloring the dots of each one in a distinguishable color
- Forecast the cycle time on future assignments
How To Use a Scatter Plot Chart to Forecast Cycle Time
One of the greatest benefits of using a cycle time scatter plot for Lean management is that it gives you the ability to forecast the outcome of future tasks. Although at first sight, it may look confusing, the chart can give you probabilistic forecasts about future performance.
For this to happen, you need to draw horizontal lines across the chart depending on the number of tasks that were finished within a specific time frame. For example, let’s say that you’ve got 100 tasks that were completed in 30 days. If 25 of them were finished in 5 days or less, while all the others took longer, you’ve got 25 percent chance to finish any future task within this time frame. Draw a horizontal line at height of the 10th day on your cycle time scatter plot.
Let’s say that 50 tasks more were completed within 10 days. The second horizontal line should mark 75 percent and should be at the height of the 10th day. The higher the percentile, the higher the chance to complete a future task within this time frame.
Whenever you are about to commit to a deadline, you just need to look at the percentile lines on your scatter plot and say that you’ve got a certain percent chance to be ready in X days/weeks/months.
Undoubtedly useful, a handmade cycle time scatter plot would require a lot of time to maintain. Thankfully, digital Kanban board platforms have implemented the chart in their software. With their help, you can set the desired time frame and get accurate data and percentiles in a few seconds.
In addition, you’ve got a number of filters at your disposal that can help you distinguish easily between various card criteria like task type, priority, assignee, and etc. This way, you can visualize with great precision the exact data that you are looking for.
The cycle time scatter plot can prove to be an amazing addition to your arsenal of analytics for Lean project management. With its help, you can get a transparent picture of the cycle time of cards that pass through your team’s Kanban board. In addition, you’ll be able to forecast how long it would take for future assignment to be completed.